Recently a gesture recognition technology is applied to and developed in various fields such as an intelligent robot, a game, a simulation, and a production technology as communication means between a human and a computer. Specifically, the gesture recognition apparatus performs image processing to a moving image obtained by imaging a hand or fingers of the human with a video camera and recognizes a series of specific movements (hereinafter referred to as gesture) of a specific portion. The computer can perform various pieces of processing according to the gesture recognized by the gesture recognition apparatus.
In the gesture recognition technology (for example, a technology in which a finger posture (gesture) of a user is recognized instead of a remote controller of a television set to remotely control an operation of the television set) applied to a user interface, it is necessary for the gesture recognition apparatus to correctly judge that a range of the movement of the user correspond to the gesture to be recognized. That is, it is necessary that the gesture recognition apparatus correctly judge start and end points of the recognition processing in the moving image in order to realize the correct gesture recognition in which the false recognition is hardly generated.
For example, in gesture recognition method and apparatus disclosed in Japanese Unexamined Patent Publication No. 09-311759, the user possesses a penlight that emits a light having a predetermined color and the apparatus recognizes the start and end of the gesture by turning on and off the penlight.
On the other hand, there is a technique of correctly recognizing the gesture by special unit without issuing the instruction to start and end the recognition processing.
For example, Japanese Unexamined Patent Publication No. 2007-087089 discloses a gesture recognition apparatus, in which a moving direction of the human's hand is grasped as an observation signal, a set of the predetermined number of observation signals is compared to a previously-prepared HMM (Hidden Markov Model) corresponding to a kind of the gesture, thereby recognizing the gesture.
In a gesture recognition apparatus disclosed in Japanese Unexamined Patent Publication No. 2007-272839, an action direction of a moving object is obtained and accumulated as a vector from continuously-input frame images to produce a vector feature quantity expressing the gesture, a state of the vector feature quantity is compared the before-and-after states to determine a state transition (progression, stagnation, and recession of the state), thereby determining whether the vector feature quantity holds as the gesture.
However, in the gesture recognition method and apparatus disclosed in Japanese Unexamined Patent Publication No. 09-311759, unfortunately it is necessary for the user who performs the gesture to possess the special light-emitting unit such as the penlight in order to use the gesture recognition apparatus.
In the pieces of gesture recognition apparatus disclosed in Japanese Unexamined Patent Publication Nos. 2007-087089 and 2007-272839, although the gesture recognition apparatus is independent of the special unit, unfortunately it is necessary to perform high-load image recognition processing equal to the original gesture recognition to all the frame images. Particularly, in order to recognize a fine gesture such as a specific finger posture, it is necessary to provide a complicated gesture recognition algorithm, which results in a problem in that the load on the apparatus is further increased. When the judgment of the start and end points of the gesture is mistakenly made, unfortunately there is a high possibility that the gesture is mistakenly recognized.